public class firstGUI {
   private Frame f;
   private Button b1, b2;

   public static void main(String[] args) {
      firstGUI myFirstGUI = new firstGUI();
      myFirstGUI.go();
   }
   public void go() {
      f = new Frame("First Gui Example");
      f.setLayout(new FlowLayout());
      b1 = new Button("Press-me");
      b2 = new Button("or me! ");
      f.add(b1); f.add(b2);f.pack();
      f.setVisible(true);
   }
}

- An event signals that something happened

- Events can be triggered by :

1. The user, using the mouse or the keyboard
2. The system, notifying changes

- Components receive events and process them accordingly

import java.awt.*;

public class AWTDemo extends Frame {
    
    private Panel myPanel;
    private Button myButton;   

    public AWTDemo() {
        this.setBounds(0, 0, 200, 200);
        myPanel = new Panel();
        myPanel.setBackground(Color.red);
        this.add(myPanel);
        
        myButton = new Button();
        myButton.setBounds(50, 50, 100, 80);
        myButton.setLabel("Click me!");
        myPanel.add(myButton);

    } // end constructor
        
public static void main(String args[]) {
   AWTDemo myFrame;
   myFrame = new AWTDemo();
   myFrame.show();
} //end static main

// this is the old way to handle events
public boolean handleEvent(Event myEvent) {
   if (myEvent.id == Event.WINDOW_DESTROY) {
      hide();
      System.exit(0);
      return true;
   }
   if (myEvent.target==myButton && 
        myEvent.id==Event.ACTION_EVENT) {
      if (myPanel.getBackground() == Color.red) {
       	  myPanel.setBackground(Color.blue);
      }
      else { 
          myPanel.setBackground(Color.red);
      }
    } //end if
    return super.handleEvent(myEvent);
  } //end handleEvent
} //end class AWTDemo